Show error on invalid image file
Add server-side http->https redirect
Check if file exists only if input changed
[#29] Handle fatal errors

- Add php shutdown handler which adds a 500 response header, so the response triggers the .error() callbacks.
- Show error and disable busy state
Fix so 5073a89d applies also if 'title' is set instead of 'imageUrl'
Unlink local cache if invalid

Might be an incomplete download or contain the result of some server
error.
Log errors with Rollbar
cleanup
Add toolinfo.json
Merge branch 'master' into deploy

Conflicts:
	composer.json
	public_html/common.php
	public_html/crop.js
	src/Image.php
mcrypt also needed
Vagrant setup - a start